The goal of this project is to determine how Connectin (Con), a cell adhesion protein, is regulated by the homeotic gene Ultrabithorax (Ubx) in the Drosophila embryo. The proposed experiments will address two specific aims: (1) to characterize the normal patterns of Ubx and Con protein distribution in the embryonic nervous system, and (2) to examine the regulation of Con by manipulating Ubx expression. I will use embryos that have loss-of-function or ectopic expression of the different protein isoforms that are products of the Ubx gene. Immunohistochemistry and confocal microscopy will be used to examine changes in Con expression and in nervous system morphology. The proposed project will augment the body of knowledge of the roles of homeotic genes and cell adhesion molecules in the development of the nervous system.